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Did you know that you can attend the first session of any of our online or in-person GMAT courses absolutely free? We\u2019re not kidding! <\/i><\/b>Check out our upcoming courses here<\/i><\/b><\/a>.<\/i><\/b><\/p>\n Welcome to the fifth installment of our Fast Math series. (Miss any earlier ones? Start here.<\/a>)<\/span><\/p>\n Make your life easier on the GMAT: Do less Math. (Yes, with a capital-M. <\/span>\u263a<\/span>) I use Math-with-a-capital-M to mean formal, textbook math.\u00a0<\/span><\/p>\n Sure, you\u2019re going to have to do some textbook math on the GMAT, but it\u2019s really not a math test. Business schools don’t expect you to have to do paper math in b-school or the real world. Rather, they\u2019re testing how you think about math. And thinking about math in the real world is a lot different than textbook, school-based math.<\/span><\/p>\n For one thing, the correct answer on the GMAT is never actually a number or a math term. The correct answer is just (A), (B), (C), (D), or (E). <\/span>How<\/span><\/i> you get to that correct letter doesn\u2019t matter in the slightest.<\/span><\/p>\n Okay let\u2019s dive into our 5<\/span>th<\/span> Principle for Fast Math!<\/span><\/p>\n <\/p>\n Peyman ate <\/span>1<\/sup>\u20445<\/sub><\/span> of the chocolates, Rishi ate 1<\/sup>\u20444<\/sub><\/span>, and Sharmad ate 1<\/sup>\u20442<\/sub><\/span>. What fraction of the chocolates are left over for me?<\/span><\/p>\n (These are students from one of my classes. Hi!!)<\/span><\/p>\n There\u2019s a reason why fractions, decimals, and percents are always taught together: They are just different forms of the same number. For example, 60% = <\/span>6<\/sup>\u204410<\/sub><\/span> = 0.6.<\/span><\/p>\n You already know all that, right? So what\u2019s my point?<\/span><\/p>\n Different math operations can be easier to do with one of these forms than another. Your job is to know which kinds of things are easier to do in which form.<\/span><\/p>\n In the problem above, I have to add together three fractions.<\/span><\/p>\n But wait! Adding fractions is super annoying because we have to find common denominators. There are three fractions with three different denominators. Ugh!<\/span><\/p>\n It\u2019s easier to add numbers in percent or decimal form. For example:<\/span><\/p>\n Only 5% of the chocolates are left for me.<\/span><\/p>\n Oh, wait, they asked for the fractional amount left. That\u2019s okay; convert back! If you have your common conversions memorized, then you already know that 5% = <\/span>1<\/sup>\u204420<\/sub><\/span>. If not, do this:<\/span><\/p>\n 5% = <\/span>5<\/sup>\u2044100<\/sub> = 1<\/sup>\u204420<\/sub><\/span><\/p>\n What skills did I need to have to do the above?<\/span><\/p>\n (1) I had to recognize that adding (or subtracting) is easier in percent or decimal form.<\/span><\/p>\n (2) I had to convert the fractions. On another problem, this might have been annoying, but this one had \u201cnice\u201d fractions. This wasn\u2019t just luck! You\u2019ll find that, on the GMAT, they\u2019re going to set these shortcuts for the people who are trying to find them.<\/span><\/p>\n (3) I had to remember to convert back to fractional form. But this was worth it to avoid having to find common denominators!<\/span><\/p>\n And, often, you don\u2019t even have to do that last step. The answers might be so far apart that I can tell which one must be right. Is 5% equal to 1<\/sup>\u204420<\/sub><\/span>, 1<\/sup>\u204410<\/sub>, or 1<\/sup>\u20445<\/sub><\/span>? I know it\u2019s not <\/span>1<\/sup>\u204410<\/sub><\/span> or <\/span>1<\/sup>\u20445<\/sub>,<\/span> so it must be 1<\/sup>\u204420<\/sub><\/span>.<\/span><\/p>\n Alternatively, the answers might actually be in percent form! Glance at them before you solve\u2014that would be a great clue to convert over to percents right away.\u00a0<\/span><\/p>\n Or the problem might be written in such a way that I\u2019m calculating the actual number of chocolates left over, so I don\u2019t have to convert to fractions again at the end. Let\u2019s say they asked how many chocolates were left and they told me that Rishi ate 10 chocolates (along with all of the original info). Rishi ate 25%, so 25% = 10 chocolates. Therefore, 100% = 40 chocolates, and my 5% would amount to 2 whole chocolates. Yum.<\/span><\/p>\n (By the way, if you feel comfortable manipulating percentages, you could go straight from 25% = 10 to 5% = 2. Think about how that shortcut works. And remember principle #1: Don’t do math till you HAVE to.)<\/span><\/p>\n Okay, now that you know that, think for a moment: If the problem requires you to <\/span>multiply<\/span><\/i>, which form do you want to use? Fractions, decimals, or percents?<\/span><\/p>\n When multiplying, it\u2019s easier to use fractions for the same reason that we didn\u2019t want to use fractions to add. When you have numerators and denominators, you can simplify before you multiply, making the numbers easier to combine. The same is true for division. For example:<\/span><\/p>\n What is 0.25 divided by 0.375?<\/span><\/p>\n Ugh. Okay, here we go.<\/span><\/p>\n Same as before: (1) Recognize that you want to use the fraction form. (2) Know your conversions. (3) Convert and solve.<\/span><\/p>\n As you continue to practice fraction-decimal-percent problems, think about where else you can make your life easier by putting the number in a different form.<\/span><\/p>\n Join us next time<\/a> for more Fast Math!<\/span><\/p>\n NEXT: <\/strong>More Fast Math for the GMAT (Part 6)<\/a><\/p>\n \u00a0<\/p>\n Can\u2019t get enough of Stacey\u2019s GMAT mastery? Attend the first session of one of her upcoming GMAT courses<\/a> absolutely free, no strings attached. Seriously.\u00a0<\/strong><\/em><\/p>\n Did you know that you can attend the first session of any of our online or in-person GMAT courses absolutely free? We\u2019re not kidding! Check out our upcoming courses here. Welcome to the fifth installment of our Fast Math series. (Miss any earlier ones? Start here.) Make your life easier on the GMAT: Do less […]<\/p>\n","protected":false},"author":6,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[873,18,929,874,52871,930,2,8],"tags":[53022,53023],"yst_prominent_words":[57255,57251,57261,57258,57253,57248,57259,57250,57249,57254,57256,57252,54388,57260,53868,57257,53781,53775,53997,53867],"class_list":["post-13758","post","type-post","status-publish","format-standard","hentry","category-for-current-studiers","category-manhattan-gmat-blog-fdp","category-gmat-prep","category-gmat-resources","category-gmat-strategies","category-gmat-study-guide","category-how-to-study","category-quant-on-gmat","tag-fast-math","tag-fast-math-for-the-gmat"],"_links":{"self":[{"href":"https:\/\/www.manhattanprep.com\/gmat\/wp-json\/wp\/v2\/posts\/13758","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.manhattanprep.com\/gmat\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.manhattanprep.com\/gmat\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.manhattanprep.com\/gmat\/wp-json\/wp\/v2\/users\/6"}],"replies":[{"embeddable":true,"href":"https:\/\/www.manhattanprep.com\/gmat\/wp-json\/wp\/v2\/comments?post=13758"}],"version-history":[{"count":7,"href":"https:\/\/www.manhattanprep.com\/gmat\/wp-json\/wp\/v2\/posts\/13758\/revisions"}],"predecessor-version":[{"id":19597,"href":"https:\/\/www.manhattanprep.com\/gmat\/wp-json\/wp\/v2\/posts\/13758\/revisions\/19597"}],"wp:attachment":[{"href":"https:\/\/www.manhattanprep.com\/gmat\/wp-json\/wp\/v2\/media?parent=13758"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.manhattanprep.com\/gmat\/wp-json\/wp\/v2\/categories?post=13758"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.manhattanprep.com\/gmat\/wp-json\/wp\/v2\/tags?post=13758"},{"taxonomy":"yst_prominent_words","embeddable":true,"href":"https:\/\/www.manhattanprep.com\/gmat\/wp-json\/wp\/v2\/yst_prominent_words?post=13758"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
\nPrinciple #5: Know when to use fractions, or decimals, or percents<\/h4>\n
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\n![\"stacey-koprince\"](\"https:\/\/cdn2.manhattanprep.com\/gmat\/wp-content\/uploads\/sites\/18\/2015\/06\/stacey-koprince-150x150.png\")
<\/a>Stacey Koprince<\/a> is a Manhattan Prep instructor based in Montreal, Canada.<\/strong> Stacey has been teaching the GMAT, GRE, and LSAT \u00a0for more than 15 years and is one of the most well-known instructors in the industry. Stacey loves to teach and is absolutely fascinated by standardized tests. Check out Stacey\u2019s upcoming GMAT courses here<\/a>.<\/em><\/p>\n","protected":false},"excerpt":{"rendered":"